Wireless telecommunications networks utilize systems, typically in the form of digitally-controlled RF transceivers, that contain both digital and RF circuits. Such systems, hereinafter referred to as a "digital/RF systems", operate to transmit information to, and receive information from, other such digital/RF systems. A typical digital RF system comprises a digital controller for controlling the system and a base-band processor (typically, a digital signal processor) for processing incoming voice and/or data signals, such as those received from a land-based network, to prepare such signals for transmission by an RF transmitter within the system. The base-band processor also serves to process signals received via an analog RF receiver within the system.
During the manufacture of digital/RF systems, as well as during their routine maintenance, the systems are tested to assure their operability. Traditionally, the digital controller and the base-band processor of each digital/RF system have been tested separately from the RF transmitter and receiver. Digital test techniques, such as Boundary-Scan testing, can be used for structurally testing the digital controller and the base-band processor. However, such digital test techniques are not suitable for testing the RF transmitter and RF receiver.
Rather, the RF transmitter and RF receiver are tested by measuring their functional response to applied stimuli. In practice, the applied stimuli may be dissimilar to the actual signals present in the transmitter and receiver during normal operation. Thus, the results achieved during testing may not represent the true operating state of the transmitter and receiver. Moreover, specialized instrumentation often must be used to measure the functionality of the RF transmitter and RF receiver, making such testing costly to carry out.
Thus, there is a need for an integrated test technique for testing both the digital and RF elements within a digital/RF system.